/*
 * Copyright 2011 Google Inc.
 * Copyright 2011 Peter Kuterna
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.peterkuterna.android.apps.devoxxsched.ui.widget;

import net.peterkuterna.android.apps.devoxxsched.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

/**
 * An {@link ImageView} that draws its contents inside a mask and draws a border
 * drawable on top. This is useful for applying a beveled look to image
 * contents, but is also flexible enough for use with other desired aesthetics.
 */
public class BezelImageView extends ImageView {

	private static final String TAG = "BezelImageView";

	private Paint mMaskedPaint;
	private Paint mCopyPaint;

	private Rect mBounds;
	private RectF mBoundsF;

	private Drawable mBorderDrawable;
	private Drawable mMaskDrawable;

	public BezelImageView(Context context) {
		this(context, null);
	}

	public BezelImageView(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
	}

	public BezelImageView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

		// Attribute initialization
		final TypedArray a = context.obtainStyledAttributes(attrs,
				R.styleable.BezelImageView, defStyle, 0);

		mMaskDrawable = a.getDrawable(R.styleable.BezelImageView_maskDrawable);
		if (mMaskDrawable == null) {
			mMaskDrawable = getResources().getDrawable(R.drawable.bezel_mask);
		}
		mMaskDrawable.setCallback(this);

		mBorderDrawable = a
				.getDrawable(R.styleable.BezelImageView_borderDrawable);
		if (mBorderDrawable == null) {
			mBorderDrawable = getResources().getDrawable(
					R.drawable.bezel_border);
		}
		mBorderDrawable.setCallback(this);

		a.recycle();

		// Other initialization
		mMaskedPaint = new Paint();
		mMaskedPaint.setXfermode(new PorterDuffXfermode(
				PorterDuff.Mode.SRC_ATOP));

		mCopyPaint = new Paint();
	}

	@Override
	protected boolean setFrame(int l, int t, int r, int b) {
		final boolean changed = super.setFrame(l, t, r, b);
		mBounds = new Rect(0, 0, r - l, b - t);
		mBoundsF = new RectF(mBounds);
		mBorderDrawable.setBounds(mBounds);
		mMaskDrawable.setBounds(mBounds);
		return changed;
	}

	@Override
	protected void onDraw(Canvas canvas) {
		int sc = canvas.saveLayer(mBoundsF, mCopyPaint,
				Canvas.HAS_ALPHA_LAYER_SAVE_FLAG
						| Canvas.FULL_COLOR_LAYER_SAVE_FLAG);
		mMaskDrawable.draw(canvas);
		canvas.saveLayer(mBoundsF, mMaskedPaint, 0);
		canvas.drawColor(Color.WHITE);
		super.onDraw(canvas);
		canvas.restoreToCount(sc);
		mBorderDrawable.draw(canvas);
	}

	@Override
	protected void drawableStateChanged() {
		super.drawableStateChanged();
		if (mBorderDrawable.isStateful()) {
			mBorderDrawable.setState(getDrawableState());
		}
		if (mMaskDrawable.isStateful()) {
			mMaskDrawable.setState(getDrawableState());
		}

		// TODO: is this the right place to invalidate?
		invalidate();
	}
}
